Hello again,
I have to second the nomination to go to 100kHz instead of 200kHz. Much more workable.
Also, either way, switching losses are to be considered, and in these fast designs gate dissipation is also usually a consideration because the mosfets gates have to be driven very hard to meet the rise and fall times.
Good mosfets drivers are a must.
Short source leads to minimize ringing which can cause the device to turn on and off several times per actual switch command which of course raises power dissipation.
Part of this also depends on how much of an overkill you want to apply to the mosfet selection. A production design would require careful consideration of cost while a one-off home built unit can go for the gusto and buy a nice hefty device that can easily handle the power 